"There's so many cars on the road that already fail every six months. To extend this to one year - who knows what could happen?
"Cars could be driving along and have their tyre blow out."
Most customers were quite happy to have their cars checked every six months, Mr Tremberth said.
"They [the Government] also figure they're going to be saving millions for drivers, but the tests will have to be a lot harder if they happen only once a year, which means the prices will go up."
The proposed options include four alternatives to streamline the warrant of fitness scheme and changes to the vehicle registration programme.
Vehicles must now be inspected every six months if older than six years. Newer vehicles are inspected annually.
With inspections often costing about $50 each, Kiwis are forking out nearly $250 million in inspection fees each year.
Proposed changes include tougher testing standards, but less frequent inspections and the introduction of demerit points penalising those who don't comply with warrant of fitness safety standards.
A further seven changes to vehicle registration are included in the document, plus new options for the Certificate of Fitness and Transport Licensing systems.
Drivers would save millions of dollars in testing fees and administration costs each year under the proposed options, the ministry says.
The AA says the changes could bring New Zealand into line with the rest of the world.
"New Zealand is the only country in the world that requires most vehicles to undergo a safety inspection every six months," spokesman Mark Stockdale said.
"Most countries only require an inspection once a year or every two years, and in many Australian and US states, there is no regular inspection at all."
Associate Transport Minister Simon Bridges said about $245 million was paid in warrant of fitness inspection fees each year.
